Method of preparing a precooked pork sausage



United States Patent METHOD OF PREPARING A PRECOOKED PORK SAUSAGE Carl A. Thommen, Western Springs, 111., assignor to Swift & Company, Chicago, 111., a corporation of Illinois No Drawing. Application November 19, 1951, Serial No. 257,187

5 Claims. (Cl. 99109) This invention relates to a process of preparing uncured pork sausage products which can be packaged and distributed to the consumer in a form requiring only a very short final cooking period immediately prior to serving.

Uncured pork sausage products have been prepared and distributed in many different forms. The most common form in which pork sausage'products have been sold is the standard pork sausage links, which are packaged fresh and must be kept under refrigeration at all times prior to consumption. The volume of sales of this product has remained practically constant despite great increases in the volume of sales of frankfurters and other sausage products. Fresh pork sausage patties and porksausage meat in bulk form are also sold, but in substantially smaller volumes. Each of the foregoing fresh pork sausage products has a relatively short storage life, requires careful supervision during distribution to prevent spoilage, and must be cooked for a relatively long period by the consumer prior to serving. Moreover, there is invariably a loss of weight of over 50 per cent during the cooking of each of the foregoing fresh sausageproducts,

The lengthy cooking time required and the very substan- "ice.

temperature of the pork sausage product exceeds the specifications of The Meat Inspection Department (M. I. D.) of the Department of Agriculture for pork products, but is discontinued before there is any appreciable external browning or crusting of the product. In performing the initial cooking operation the several time and temperature factors and other conditions must be controlled so that external browning and crusting can be delayed until the desired internal temperature .is attained. In this manner it is possible to obtain a pork sausage product which must only be heated for a very short period by the consumer prior to serving and yet produce a product which has substantially improved texture, flavor and aroma, and which retains a much larger percentage of its original weight. j

In practicing the present invention the exact conditions employed will depend upon several variables such as the composition of the pork sausage product, the form of the pork sausage product and the temperature of the product prior to heating. For a pork sausage link product of standard formulation which has been chilled to a temperature of approximately 38 F. it has been found that internal temperatures between 160 F. and 200 F. may be satisfactorily employed, with a temperature of about 170 F. being preferred. The latter temperatures are substantially lower than those generally attained during the cooking of fresh pork sausage by the consumer.

those responsible for souring. Also, an essential functial shrink of the fresh pork sausage products during cooking have apparently reduced the popularity of these 'products with respect to the competitive products, such as bacon and frankfurters, and other meat products which can be prepared in a relatively short time.

More recently, pork sausage links have been cooked in sealed containers such as the consumer type tin cans. Canned pork sausage links, however, do not have the desired texture or flavor expected of fresh pork sausage,

and consequently there has not been a widespread consumer demand for the canned product.

It is the object of the present invention, therefore, to overcome the foregoing defects of the prior art and to provide an improved process for the preparation and distribution of pork sausage products.

Another object of the invention is to provide a process enabling a more appetizing pork sausage product to reach the consumer in a form which requires a minimum amount 1 of preparation prior to serving.

Still another object of the invention is to provide a process for preparing a pork sausage product which loses a substantially smaller percentage of its weight during the cooking operations.

A further object of the invention is to provide a pork sausage product which has a substantially prolonged shelf life and retains its natural flavor for an extended period.

A still further object of the invention is to provide a 65 The foregoing and other objects can be accomplished in general by performing an initial critical cooking operation on the pork sausage product prior to packaging tial cooking operation is carried out so that the internal tion of the initial cooking operation is the formation of a layer of denatured proteinaceous material completely enclosing the exterior surface of the pork sausage product by subjecting to dry heat without. however, substantially browning or crushing the product. In this manner the interior of the product is protected against oxidation and recontamination, and at the same time excessive losses of the natural juices and moisture of the pork sausage meat are prevented during storage and subsequent browning by the consumer.

The actual cooking time during the initial cooking "'operation will, of course, depend upon the internal temperature desired to be attained in the product, theinitial temperature of the product, the form and composition of the product, and the particular heating apparatus used. For theabove mentioned pork sausage link product, an internal temperature of F. can be attained within a period of between about 6 and 45 minutes in an oven having an internal temperature ranging between about 250 F. and 450 F. An oven temperature of approximately 350 F. is frequently found to be a satisfactory temperature. The heating operation may be performed in conventional oven heated by gas, steam coils, radiant coils, or any other dry heating means desired, including heating by induction and dielectric heating. However, since there are a great many variables, it is extremely difficult to arbitrarily state the temperature, time, and other specific operating conditions in the initial cooking operation. The operating conditions are readily determinable,

nevertheless, by one skilled in the art after becoming familiar with the herein disclosed principles.

The most practical method of determining the operating conditions in a particular heating apparatus and for a particular'product is to process a series of "test: lots of and distributing the product to the consumer. Theini- 'i the particular product in the oven having a 'known interior temperature for varying periods until the product has attained a definite internal temperature within the specified temperature range. Heating of each test lot is terminated when the interior temperature of the product has attained a progressively higher temperature and 4,. veyor and carried through a heating tunnel having a temperature of about 300 F. The links were allowed to remain in the tunnel until they acquired an internal temperature of about 170 F. to insure the destruction of preferably at about 10 F. intervals. Eachtestlot is-then 5 microorganisms and the production of a fully-cooked stored. at 40 E, which simulates actual temperatures enproduct, and also acquired the necessary external proteccountered during distribution and at regular intervals tive layer of denatured protein. samples of. each test lot are browned for a period of 3min: The pre-cooked pork sausage links were then conutes in. a skillet, in the same manner as the consumer veyedpast packaging stations where operators placed the would finally cook the product, and the samples then pork sausage links into 8 ounce containers with each scored for appearance, aroma, and. flavor. The peroxide package containing 8. pro-cooked pork'sausage links. The value ofeach sample may also be determined as. an obindividual packages. were then placed in. chill. and therej ective measure of oxidative rancidity. After. aperiod of after were ready for shipment. 3 weeks it will be readily evidentwhich. of, the operating, In other tests following substantially the foregoing conditions-produced. a product having thernost desirable procedure, substantially the same pre-cooked pork properties. sausage product was; produced by forming the links with It is, of course, understoodthat in each. instance the the conventional pork sausage stuffing machine using heating-in. the. initial. cooking operation. is. discontinued cellulose casings. After the links were chilled to about before the product attainsa significant. degree of brown- 0 F.,, the casings were. stripped and the skinless links ing or crusting. When the product is heated during the conveyed through a, conventional gas heated ovenwhere initial cooking period in the foregoingmanner it will be in the. links were pro-cooked to the same degree as. in. found that the productwill have lost only between 30 and Example I in dry heat. The pre-cooked links were then 40l-per. cent of. its.initial weight and will have retained suf.- packaged in the same manner as described in Example I. fi'cient amounts. of moisture and fat so that the finally In addition to having substantially improved flavor and browned product will be'much more plump and tender aroma, the pro-cooked pork sausage products produced.- than the. regular fresh pork sausage productafter cooking by the. present invention have unusual properties notunder the most. favorable conditions possible. The refound in any ofthe other present pork sausage products. sulting improvement in flavor, aroma and texture of the, Thus, as a result of careful studies of comparative lots product. of. the. present invention is very striking. Like.- of fresh pork sausage and pre-cooked pork sausage, it was wise, the. absence of any noticeable decrease in sizeof the found that. the fresh pork sausage are noticeably off-- pro-cooked pork sausage product during the final cookflavor as a result of souring and were in an unpalatable ingoperation-is inmarked contrast to the very great-shrink condition within about 5 to 7 days after being manuwhich occurs when fresh pork sausages are cooked in the factored and held at a temperature of 40 F. The preconventional manner. There actually appears to be an cooked pork. sausage described. herein, however, retains increasein size of the pre=cooked product during the final substantially all of. its initial flavor and aroma for a period cooking operation. in excess of 20 days under the same 40 storage condi-- So that. the present invention can be thoroughly untions. Theresults of a side-by-side comparison are given derstood, thefollowing specific example is given without, in Table-.1.

Table I Y Four Days Old Six Days Old Eight'Days Old Eleven Days Old Twenty Days Old Product Aroma Flavor Aroma Flavor Aroma Flavor Aroma Flavor Aroma Flavor Pre cooked pork sausagecontaining natural sage andpepper l 8.10 8.0 7. 2 7. 8 6. 7 6.15 7.3 7. 8 7. 3 7. 1 Fresh pork sausage containing natural sage and pepper; 6. 2 4. z; 6 1; 7' Sour Pre-cooked pork sausage containing spice a E extractives of sage and pepper plus 0.022%

Sustane antioxidant 7.1 7. 5 7:0 7.3' 655" as 6.4 6:7 6:3 6L4 Pre-cooked pork sausage containing spice extractives of sage audpepper 5.1.. 5. .6 3; 2 1.7 Rancid} however, limiting the invention to the precise-details and. In. conducting. the. above comparative keeping-quality conditions. set forth. tests, the; same porkrsausage formulationwas usedi-neacl' EXAMPLEI product, t l1e. same. natural and commercial spice extrac A pork sausage meat'forrnulation was prepared-bypasstivfs were used as i ingredlents same ingthe convention-al pork sausage meat ingredients in the 40 stoiagg common was employed l each standard proportions through a standard hasher having a In evaluating-leach sample after the spe'clfigd'number' of large. opening in the discharge plate. The comminuted dayshad elapsad an T test panel scored each meat. was subjected. toa vacuum, and thereaftermixed of i products .after It had been finally on for:6 minutesinthevstandard sausagernixer with approxii bemg excelient; very good; goo.d; mately 7 ounces of: natural sage and natural pepper forshghily goo-d; border-line plus; bordel'hne' 11mins; each. 100 pounds. meat. Water, sugar and salt were shghtiylimor; p very poor; .repulswe added. in; the conventional amounts. The foregoing The immoxldant used one of the tests 15 a coarse: mixture; was then passed through a conventional merclalppmduct and Includes a i f i Of buty1 i grinder. having small. openings in the discharge plate, and dmxyamsolgprop-ylganate and cltncfi w m the finely ground meat'wasvacuumized for approximate-- pmPybner lycol as: a solvent. Other antlrox dants: as ly 10. minutes'inan atmosphere having a pressure of about sodl-um and Such @mkoxldant contamns 0115 25 in h gfe r as wheat germ. oil, soybean. oil, and. cottonseed oil in. an

The meat" was then fed into a stufling' machine, which amount ofTabollti P cent y be usedi t h d h meat. i a ffi hi i h It will be evident from the data shown in- Table I that shaped the sausage. into. skinless links approximately the-fresh porksausage became sour and unpalatable after 3% inchesilong and weighing-between. l and 2 ounces, so y g While p P that each: pro-cooked link would Weigh 1' ounce. The remained'in a marketable condition forover 20' days at formedlinks were-then discharged onto=a continuous G0 the same storage temperature.

greases" The data of Table I also show that there is aremarkable difference in the keeping qualities of pre-cooked pork sausage containing natural seasoning as compared with the pre-cooked pork sausage which contains the spice extractives conventionally used in the preparation of the regular fresh pork sausage products. The spice extractives used were the conventional oleo resins and volatile oils which are extracted from the natural spices by wellknown processes and contain the active flavoring ingredients of the natural seasoning. Thus, the pre-cooked pork sausage containing the spice extractives used in fresh pork sausage was distinctly off-flavor in days, whereas the pre-cooked pork sausage containing natural seasoning remains in very acceptable condition for over 20 days. The foregoing unusual and very unexpected result appears to be due to certain inherent anti-oxidant properties peculiar to the natural seasoning ingredients incorporated in the pre-cooked pork sausage. It was altogether unexpected that the anti-oxidant properties of the natural spices would affect the keeping qualities of the pre-cooked pork sausage because of the very minor percentage of seasoning used, and it is even more remarkable since it would normally be expected that the anti-oxidant properties would be destroyed by the heat treatment to which the product is subjected during the pre-cooking operation.

The deficiency in anti-oxidant properties of the spice extractives used in pork sausage may be at least partially overcome by the addition of an anti-oxidant material to the prepared seasoning prior to incorporating in the pork sausage meat. The extent to which the anti-oxidant improves the storage life of the pre-cooked pork sausage is evident from the data shown in Table I. Despite the later improvement, however, it is preferred to employ natural seasoning, such as natural pepper and sage, both for their greater effect on the keeping qualities of the product and upon the improved flavor and aroma of the final product.

In addition to the improvement in keeping qualities exhibited by the pre-cooked pork sausage as compared with the fresh pork sausage products, the pre-cooked pork sausage also exhibits substantially increased nutritive value. A comparison of the nutritive elements found in fresh pork sausage, and pro-cooked pork sausage, after each was finally cooked, is shown in the following Table II.

Table II Pork Sausage Cooked for Serving An examination of the data of Table II shows that the pre-cooked product as compared with the regular cooked fresh pork sausage retains appreciably more protein. The pre-cooked pork sausage also retained more thiamine and riboflavin. It is also probable that other vitamins are also retained in larger amounts.

Another very significant property of the pre-cooked pork sausage which is not found in fresh pork sausage products is the property of the pre-cooked pork sausage to retain a substantially greater portion of its initial weight after being finally cooked or browned by the consumer.

Extensive tests of fresh pork sausage products which were carefully prepared'in accordance with'therecom-. mended cooking procedure are shown in Table III.

Table III Lot No. 1 Lot No. 2

Uncooked weight, grams 454 453 Cooked weight, grams-.- 199 196 Dripping weight, grams 81 35 Dripping shrink, percent 17. 8 7. 7 Total cooking shrink, percent 56. 2 56. 7

As indicated by the data in Table III, it is customary for fresh pork sausage to lose over 50 per cent of its initial weight during the cooking operation.

Similar weight-loss tests conducted on pre-cooked pork sausage prepared in accordance with the present invention and having substantially the same formulation as the fresh pork sausage used to obtain data in Table III.

indicate that the pre-cooked pork sausage after final cooking loses a total of between 40 and 45 per cent of its initial weight.

Table IV gives the result of a typical weight-loss study of fresh and pre-cooked pork sausage, and includes the percentage loss in weight during the initial pre-cooking operation and the final weight loss during the browning As indicated in Table IV, the pre-cooked pork sausage product after final cooking invariably results in yields which are substantially larger than those of the fresh pork sausage product after cooking. This is a very substantial economical saving to the consumer and to the meat industry in general. is able to put to a useful purpose only a very small percentage of the fat rendered from fresh pork sausage during the cooking thereof, the commercial processor, be-

cause of his more careful control and more efiicient meth- 0d of handling, is able to recover and save substantially all of the fat rendered during the initial pre-cooking operation.

In order to show the critical influence which the internal cooking temperature and the natural spices have on the keeping qualities of pre-cooked uncured fresh pork sausage, two test lots of pork sausage links were prepared as described herein, with one containing natural sage and natural pepper and theother containing the conventional spiceextraetives of sage and pepper which are used in fresh pork sausage. A portion of each lot was heated to an internal temperature of F. and the peroxide number of the product determined after holding at 40 F. for 3, 5 and 7 days. The peroxide number is a measure of the development of oxidative rancidity in the fats and oils, and technically designates the milliequivalents of peroxide per kilogram of fat. Additional portions of the test lots were heated at higher temperatures up to an internal temperature of Also, while the consumer:

arouses 200 F. The results of the foregoing study are given in Table V.

Table V Peroxide Number Cooking Spice Temperature Three Five Seven Days Days Days Old Old Old Natural 0. 81 0. 48 0. 46 Spice Extractives O. 31 2. 50 5. 6O 0. 97 0. 58 0. 29 2. 95 2. 80 3. 90 0. 64' 0.26 0.20 Spice Extractives 3.07 3. 70 2. 40 Natural l. 08 0.87 0. 57 Spice Extractives 7. 66 4. 40 4. 20 N t al 0.85 0. 44 0.87 3. 24 4. S 26. 60 Na ur 0.77 0.51 0.82 Spice Extractives 6.07 5.30 21.16

It will be evident that heating to' an internal temperature of 1'70'F. produces the most stable product with the lowest peroxide value. While the product heated to an internal temperature of 150 F. did not turn rancid at the end of 7 days, it was unsatisfactory because of the development of a sour condition therein.

The herein-described process and product of the present invention makes it possible for the commercial processor to provide the consumer with a new pork sausage product having greater utility than any previous pork sausage product, since it may be kept for a substantially longer period without spoiling, or may be kept under less rigid storage conditions than any previous fresh pork sausage product. The invention also makes it possible for the consumer to obtain after only a short final cooking operation a pork sausage product which is more appetizing and nutritive because it contains a greater proportion of the natural flavor and nutritive components, of the sausage meat and is not cured or smoked in order to improve its keeping qualities. The consumer also derives additional benefits because the present invention permits him to prepare an improved fully-cooked pork sausage product in a much shorter time than previously possible and without absorbing the customary large shrink in weight during the cooking process.

While the herein-disclosed embodiment of the present invention has been more particularly concerned with the preparation of pork sausage links, it should be understood that. pork sausage products in the various other forms may also be produced. For example, pork sausage patties and pork sausage meat in bulk form can also be. pro-cooked and distributed to the consumer in the same manner as the herein disclosed pork sausage links.

Obviously, many modifications and variations of the invention as hereinbefore set forth may be made with out: departing from. the spirit and scope thereof, and therefore only such limitations should be imposed as are indicated in the appended claims.

I claim:

1. A method of cooking a fresh uncured, unsmoked pork sausage product comprising forming a pork sausage formulation by mixing pork meat containing lean and fat, spices, sugar, salt, and Water; shaping the pork sausage formulation into a predetermined sausage form, subjecting the said sausage form to a dry heat treatment at a temperature between 250 and 450 F. and a period of between 6 minutes and 45 minutes, and adjusting the foregoing heating conditions so thatthe interior temperature of the said sausage form. reaches between and 200 F. before the surface area. of the said sausage form is appreciably browned and crusted, said heat treatment. sub stantially destroying the microorganisms responsible for souring offporksausage and forming a layer of denatured proteinaceous material on the exterior. surface of said sausage forms andterminating the said heattreatmen't before the said sausage form has lost in excess of 40 per cent ofi'ts original weight.

2. A process asdescribed in claim 1, wherein the spices are selected from the group consisting. of natural spices and spice extracts with asmall amount of a fat antioxidant.

3,. A process as. described in claim 1 wherein the heat treatment is terminated whenaninternal temperature of F. is attained insaid sausage 4.v A method of preparing aprecooked pork. sausage suitable for distribution as a consumer item requiring only a short cooking period to brown the product before serving, which comprises subjecting the sausage to a cooking operation under conditions of dry heat at a temperature in excess of 250 F. to bring the sausage to an internal temperature of about 160 F.180 F. before the surface of the sausage is appreciably browned and crusted to form a protective layer of denatured: proteinaceous material on 'the exterior surface of the sausage, and terminating said heating before. the loss in weight of the product is in excess of about 40%, the temperature and time of said cooking operation being correlated to produce a precooked sausage which is plumpand can be browned by a short cooking period with substantially less cooking loss than in. cooking ordinary fresh pork sausage.

5. A. method of preparing a precooked pork sausage suitable for distribution asa consumer item requiring only a short cooking period to brown the product before serving which comprises. subjecting the sausage to a cooking operation under conditions of dry heatat a temperature in excess of 250 F. for a period between six minutesand forty-five minutes to'bring' the sausage to an internal temperature of about160 F.200 F. before the surface of the sausage is appreciably browned and crusted to form a protective layer of denatured proteinaceous material on the exterior surface of the sausage, and terminating said heating before the loss in weight of the product is in excess of about 40%, the temperature and time of said cooking operation being correlated to produce a precooked sausage which is plump and can be browned by a short cooking period with substantially less cooking loss than in cooking ordinary fresh pork sausage.

References Cited in the file of this patent UNITED STATES PATENTS 1,009,953 Boyle Nov. 28, 1911 1,964,011 Vogt June 26, 1934 2,182,211 Paddock Dec. 5, 1939 2,199,584 Bemis May 7, 1940 2,355,548- Musher Aug. 8, 1944 2,507,486 Weissenbach May 9, 1950 2,685,518 Prohaska Aug. 3, 1954 OTHER REFERENCES Food Industries, October 1942, page .49, article en titled Antioxidant for Pork. 

1. A METHOD OF COOKING A FRESH UNCURED, UNSMOKED PORK SAUSAGE PRODUCT COMPRISING FORMING A PORK SAUSAGE FORMULATIN BY MIXING PORK MEAT CONTAINING LEAN AND FAT, SPICES, SUGAR, SALT, AND WATER; SHAPING THE PORK SAUSAGE FORMULATION INTO A PREDETERMINED SAUSAGE FORM, SUBJECTING THE SAID SAUSAGE FORM TO A DRY HEAT TREATMENT AT A TEMPERATURE BETWEEN 250* AND 450* F. AND A PERIOD OF BETWEEN 6 MINUTES AND 45 MINUTES, AND ADJUSTING THE FOREGOING HEATING CONDITIONS SO THAT THE INTERIOR TEMPERATURE OF THE SAID SAUSAGE FORM REACHES BETWEEN 160* AND 200* F. BEFORE THE SURFACE AREA OF THE SAID SAUSAGE FORM IS APPRECIABLY BROWNED AND CRUSTED, SAID HEAT TREATMENT SUBSTANTIALLY DESTROYING THE MICROORGANISMS RESPONSIBLE FOR SOURING OF PORK SAUSAGE AND FORMING A LAYER OF DENATURED PROTEINACEOUS MATERIAL ON THE EXTERIOR SURFACE OF SAID SAUSAGE FORMS AND TERMINATING THE SAID HEAT TREATMENT BEFORE THE SAID SAUSAGE FORM HAS LOST IN EXCESS OF 40 PER CENT OF ITS ORIGINAL WEIGHT. 